Debian sysvint-utils package will continue to have that file. That stops any messy procps splits and putting one part into Essential etc.

This may mean that one distributions pidof doesn’t quite work like anothers, but that has been like that already; which is why when I discussed the change as upstream I wondered where they found some of those flags I don’t have.

Procps version 3.3.9 was released today. As there has been some API changes and fixes which means the library has changed again. There is a fine balance between fixing or enhancing library functions and keeping the API stable, with the added problem it wasn’t a terribly good one to start with.